甘肃中部雨养农业区土壤水分预测模式的研究

采用联合国粮农组织（ＦＡＯ）最新推荐的计算农田蒸散量的彭曼－蒙蒂斯公式（ＦＡＯ－ＰＭ）,选取甘肃中部雨养农业区定西１９８０～１９９５年的常规气象资料和１９９０～１９９５年固定地段０～１００ｃｍ的土壤湿度资料,对水平衡和Ｙ．Ｍ安格斯坦土壤水分预测模式进行对比分析,认为后者适宜于本地区的土壤水分预测,并分析了误差原因     

TOGA—COARE强化期（IOP）西太平洋海域的辐射特征

该利用ＴＯＧＡ－ＣＯＡＲＥ强化观测期（ＩＯＰ）所获得的辐射观测资料（１９９２年１１月１０日－１９９３年２月１８日），对考察点（２°１５′Ｓ，１５８°００′）的辐射分量进行了分析，其中包括总辐射、直接辐射、散射辐射、海表长波辐射、大气逆辐射、海表反射辐射春反照率、净辐射及有效辐射。     

青藏高原地区大气顶净辐射与地表净辐射的关系

地表净辐射为地气系统净辐射与大气层净辐射之差。对大气层净辐射作不同的假定，可将地表净辐射与大气顶辐射收支之间的关系表示成不同的形式。本文利用１９８２年８月—１９８３年７月青藏高原地区地面辐射收支观测资料及同期ＮＯＡＡ－７辐射收支资料，用统计方法讨论了大气顶净辐射与地表净辐射之间的相关性，建立了两者之间的回归方程，并在此基础上分析了青藏高原地区月平均地表净辐射的时空分布特征。     

TOGA－COARE强化期（IOP）西太平洋海域的辐射特征

该文利用ＴＯＧＡ－ＣＯＡＲＥ强化观测期（ＩＯＰ）所获得的辐射观测资料（１９９２年１１月１０日—１９９３年２月１８日），对考察点（２°１５′Ｓ，１５８°００′Ｅ）的辐射分量进行了分析，其中包括总辐射、直接辐射、散射辐射、海表长波辐射、大气逆辐射、海表反射辐射及其反照率、净辐射及有效辐射。结果表明：和其它地区（如高原）比较，观测点的总辐射、直接辐射均很强；反射率小，晴天平均为０．０４—０．０５，阴天为０．０６—０．０８；海表长波辐射大而日变化小，大气逆辐射强而日变化大；有效辐射小而净辐射大。     

资料通讯

资料通讯国家自然科学基金委员会地球科学部南京气象学院大气资料服务中心第４卷第１期（总第１０期）１９９７年１２月ＥＣＭＷＦ数值模拟资料ＣＤ┐ＲＯＭ和ＣＭＡＰ降水资料介绍１ＥＣＭＷＦＣＤ┐ＲＯＭ这些ＣＤ－ＲＯＭ上存放着选自ＥＣＭＷＦ（欧洲中期预报中心）“...     

利用卫星可见通道反演整层大气气溶胶光学厚度

本文提出了一种基于大气辐射传输方程，利用ＮＯＡＡ－１４极轨卫星甚高分辨率辐射计见光单通道反射率资料，运用低光谱分辨率大气辐射传输模式程序反演晴空和上、均匀下垫面上的气象能见度和大气气溶胶光学厚度的算法。     

海南岛气象辐射的年变化特点

利用1992－2000年的观测资料研究了海口、三亚的气象辐射特点。结果：指出，总辐射和反射辐射具有抛物线分布特点，净全辐射全年均为正值，各辐射量的9年平均值具有双峰型特点。     

利用NOAA卫星HIRS探测器监测东亚地区辐射收支的研究

地球－大气系统的辐射收支是描述地球和宇宙空间能量交换的重要参量，也只有从卫星平台才能直接观测大气顶的地球－大气系统的辐射收支。目前，长期的地－气系统射出长波辐射序列资料是从美国ＮＯＡＡ极轨业务气象卫星的甚高分辨率扫描辐射计测量中计算的，精度不能满足气候监测的要求。本文根据美国ＮＯＡＡ卫星高分辨率红外大气探测器（ＨｉｇｈＲｅｓｏｌｕｔｉｏｎＩｎｆｒａｒｅｄＳｏｕｎｄｅｒ，缩写为ＨＩＲＳ）测量资料，研究了从中推算地球大气系统辐射收支的方法，并对计算出的１９９１年１月份东亚地区的地－气系统的辐射收支各参量、白天和夜间射出长波辐射差别分别进行了对比分析。结果表明，此方法计算的辐射收支分量，能揭示云和地球－大气系统的辐射分布特征及其分布细节，是进行区域气候研究的有效资料。     

中国地—气系统净辐射的气候特征

根据ＥＲＢＥ和ＩＳＣＣＰ资料讨论了总云量等因子对地－气系统净辐射的影响，分析了地－气系统净辐射与其各分量及地表净辐射的相关联系。发现行星反射率和地－气短波吸收辐射对气－气净辐射的影响最大，而云和纬度的作用主要通过该两因子变化表现出来，ＯＬＲ的作用则相对较弱。地－气净辐射与地表净辐射的相关性也较明显。文中还就地－气净辐射在全国的地理分布作了分析。各地区地－气净辐射的年变曲线均为简单的夏大冬小型，云等     

中国地－气系统净辐射的气候特征

根据ＥＲＢＥ和ＩＳＣＣＰ资料讨论了总云量等因子对地－气系统净辐射的影响，分析了地－气系统净辐射与其各分量及地表净辐射的相关联系。发现行星反射率和地气短波吸收辐射对地－气净辐射的影响最大，而云和纬度的作用主要通过该两因子变化表现出来，ＯＬＲ的作用则相对较弱。地－气净辐射与地表净辐射的相关性也较明显。文中还就地－气净辐射在全国的地理分布作了分析。各地区地－气净辐射的年变曲线均为简单的夏大冬小型，云等因素的影响主要造成最大值出现月份的推移。     

湖北省潜在蒸散估算模型对比

利用湖北省74个气象站1961~2011年逐日气象资料,通过与FAO56-Penman-Monteith(FAO-PM)模型潜在蒸散估算结果对比,从月、季、年际变化及不同干湿状况条件比较了PriestleyTaylor、Hargreaves及Thornthwaite 3种简化的经验模型在湖北省的适用性。结果表明:3种简化模型与FAO-PM模型计算的逐月潜在蒸散均存在一定偏差,Thornthwaite模型偏差最大且冬夏季偏差反位相,Priestley-Taylor模型偏差最小,Hargreaves模型各月间的偏差最为稳定。3种简化模型与FAOPM模型估算结果具有良好的线性关系,且在各区域间相对稳定,但不同季节和干湿状况下各有差异,其中Hargreaves模型各季节间和不同干湿状况下与FAO-PM模型的关系均最为稳定。在年际变化上,Priestley-Taylor和Hargreaves模型与FAO-PM模型计算结果年际波动基本一致,Thornthwaite模型与FAO-PM模型计算结果尽管在量值上较为接近,但年际波动偏小;Priestley-Taylor和FAOPM模型年潜在蒸散趋势变化基本一致,Hargreaves模型年潜在蒸散趋势变化微弱,而Thornthwaite模型年潜在蒸散趋势变化与FAO-PM模型相反。建议在湖北省气象资料匮乏或不便应用的情况下,作物模拟模型及气候变化等研究中采用Priestley-Taylor估算模型,日常干旱监测及水资源规划中采用Hargreaves模型,干湿气候区划等工作中可采用Thornthwaite模型。同时,使用中应基于FAO-PM模型对经验模型进行适当订正,模型订正应建立在季节或月尺度。     

CLIMATOLOGICAL STUDIES ON NET RADIATION IN CHINA

An established climatic calculation scheme for estimating the components of surface radiation budget is conducted at 223 stations throughout the country.The spatial patterns of net radiation (NR) and its components suggest that the high-value belt is steadily situated over the Yarlung Zangbo Basin in the southern Qinghai-Xizang Plateau and over the eastern Inner Mongolian Plateau,with the low-value belt over Sichuan-Guizhou mountainous temain.The pattern changes a little with the transition of seasons.Temporally,the NR's annual changes,especially its maximizing month,are closely related to the coming of rainy season.The relative computation emor is 2.7% for global radiation (GR).4.0% for surface albedo(SA),9.4% for effective radiation (ER),and 8.9% for NR.     

Comparison of the performance of net radiation calculation models

Daily values of net radiation are used in many applications of crop-growth modeling and agricultural water management. Measurements of net radiation are not part of the routine measurement program at many weather stations and are commonly estimated based on other meteorological parameters. Daily values of net radiation were calculated using three net outgoing long-wave radiation models and compared to measured values. Four meteorological datasets representing two climate regimes, a sub-humid, high-latitude environment and a semi-arid mid-latitude environment, were used to test the models. The long-wave radiation models included a physically based model, an empirical model from the literature, and a new empirical model. Both empirical models used only solar radiation as required for meteorological input. The long-wave radiation models were used with model calibration coefficients from the literature and with locally calibrated ones. A measured, average albedo value of 0.25 was used at the high-latitude sites. A fixed albedo value of 0.25 resulted in less bias and scatter at the mid-latitude sites compared to other albedo values. When used with model coefficients calibrated locally or developed for specific climate regimes, the predictions of the physically based model had slightly lower bias and scatter than the empirical models. When used with their original model coefficients, the physically based model had a higher bias than the measurement error of the net radiation instruments used. The performance of the empirical models was nearly identical at all sites. Since the empirical models were easier to use and simpler to calibrate than the physically based models, the results indicate that the empirical models can be used as a good substitute for the physically based ones when available meteorological input data is limited. Model predictions were found to have a higher bias and scatter when using summed calculated hourly time steps compared to using daily input data.     

参考作物蒸散量的多种计算方法及其结果的比较

分别用 FAO Penman- Monteith公式 (模型 1 )、FAO Penman 修正式 (模型 2 )和国内Penman修正式 (模型 3)计算了泰安和西峰两地的参考作物蒸散量 ,对 3种方法的计算结果进行了比较 .模型 1得到的参考作物蒸散量大于后 2种模型 ,导致不同模型计算偏差的原因是 3种模型各自选用了不同的辐射项和动力项计算式 ,且计算偏差随季节和地理条件而变 .建议计算区域参考作物蒸散量用模型 1 ,计算单站逐日参考作物蒸散量 3种模型都可用 .     

Influence of non-feedback variations of radiation on the determination of climate feedback

Recent studies have estimated the magnitude of climate feedback based on the correlation between time variations in outgoing radiation flux and sea surface temperature (SST). This study investigates the influence of the natural non-feedback variation (noise) of the flux occurring independently of SST on the determination of climate feedback. The observed global monthly radiation flux is used from the Clouds and the Earth's Radiant Energy System (CERES) for the period 2000–2008. In the observations, the time lag correlation of radiation and SST shows a distorted curve with low statistical significance for shortwave radiation while a significant maximum at zero lag for longwave radiation over the tropics. This observational feature is explained by simulations with an idealized energy balance model where we see that the non-feedback variation plays the most significant role in distorting the curve in the lagged correlation graph, thus obscuring the exact value of climate feedback. We also demonstrate that the climate feedback from the tropical longwave radiation in the CERES data is not significantly affected by the noise. We further estimate the standard deviation of radiative forcings (mainly from the noise) relative to that of the non-radiative forcings, i.e., the noise level from the observations and atmosphere–ocean coupled climate model simulations in the framework of the simple model. The estimated noise levels in both CERES (>13 %) and climate models (11–28 %) are found to be far above the critical level (~5 %) that begins to misrepresent climate feedback.     

地面有效辐射气候学模型评估和参数优化

基于中国19个辐射站1993-2012年的地面辐射平衡资料和气象资料,分析评估了布朗特法、彭曼法、别尔良德法、FAO24法、FAO56-PM法、邓根云法和童宏良法7种参数化方案计算中国地面有效辐射的适用性;并以均方根误差最小为目标函数,利用步长加速法和多元回归法迭代求解最优参数,建立适合于中国的最优参数化逐日有效辐射估算方法。结果表明:参与评估的7种方案都不同程度低估了中国的有效辐射;从全中国总体误差水平看,童宏良法的平均绝对百分比误差和均方根误差小于其他6种方案,分别为27.0%和24.5 W/m2,估算效果较好;其次是彭曼法和邓根云法;FAO56-PM法精度较低,不适用于中国的有效辐射估算。针对单站来说,邓根云法在东部平原地区的精度最高,童宏良法由于考虑了海拔高度的订正,适用于西部高原地区。相关分析表明水汽压是影响有效辐射估算误差的最关键因素,因此根据水汽压的地理分布规律,分东部区和西部区建立分区方案。基于观测资料建立的全中国方案和分区方案的均方根误差分别为20.8和21.4 W/m2,精度均高于已有参与评估的7种方案;而且在绝大多数站点,分区方案的误差小于全中国方案,所以划分东部区和西部区进行有效辐射模型参数化很有必要。同时发现,分区方案在西部区明显优于邓根云法,在东部区明显优于童宏良法,因此推荐其作为中国有效辐射的计算方法。      

云天地表总辐射和净辐射瞬时值的计算方法

为减少计算机时,满足实时预报要求,全球数值预报模式中的辐射计算频率通常设定为三小时。这样处理会大大减少计算量,但也同时导致较大辐射日变化偏差,并影响模式对地面能量平衡,对流及降水的模拟。为改进这一缺陷,我们开发了一种辐射快速计算方案,可用于计算瞬时地面太阳总辐射和净辐射,使到达地面的太阳辐射计算可与模式积分同步进行,从而改善地面太阳辐射日变化模拟。本文介绍云天的计算方法。该方案所用的输入变量均为预报模式或卫星观测所能提供的量。结果表明：该方案既可用于数值预报模式也可利用观测资料独立计算地面太阳辐射。经与美国能源部大气辐射观测资料检验,该方案的精度很高,地面总辐射瞬时值的平均计算误差小于7%。     

THEORETICAL CALCULATION MODEL OF SHORTWAVE RADIATION FOR THE EARTH-ATMOSPHERE SYSTEM AND ITS TESTING RESULTS

On the basis of radiation transfer theory,adopting improved two-stream algorithm incorporated with addingalgorithm,we build up a theoretical calculation model of shortwave radiation for the earth-atmosphere system whichcan be applied with satellite data.The model can calculate direct solar radiation,scattering solar radiation,heating rateand other physical quantities of radiation field at every layer of the atmosphere and on the earth's surface,if the under-ground reflectance or the planetary albedo obtained from satellite can be known.The model can be used in clear orcloudy atmosphere,and its calculating speed is fairly fast.We think that the model can be incorporated into large-scaleand mesoscale climatic models for the consideration of radiation calculation,and also it is useful for the utilization of so-lar energy.     

Retrieving daily global solar radiation from routine climate variables

Solar radiation is an important variable for studies related to solar energy applications, meteorology, climatology, hydrology, and agricultural meteorology. However, solar radiation is not routinely measured at meteorological stations; therefore, it is often required to estimate it using other techniques such as retrieving from satellite data or estimating using other geophysical variables. Over the years, many models have been developed to estimate solar radiation from other geophysical variables such as temperature, rainfall, and sunshine duration. The aim of this study was to evaluate six of these models using data measured at four independent worldwide networks. The dataset included 13 stations from Australia, 25 stations from Germany, 12 stations from Saudi Arabia, and 48 stations from the USA. The models require either sunshine duration hours (Ångstrom) or daily range of air temperature (Bristow and Campbell, Donatelli and Bellocchi, Donatelli and Campbell, Hargreaves, and Hargreaves and Samani) as input. According to the statistical parameters, Ångstrom and Bristow and Campbell indicated a better performance than the other models. The bias and root mean square error for the Ångstrom model were less than 0.25 MJ m² day^?1 and 2.25 MJ m² day^?1, respectively, and the correlation coefficient was always greater than 95 %. Statistical analysis using Student’s t test indicated that the residuals for Ångstrom, Bristow and Campbell, Hargreaves, and Hargreaves and Samani are not statistically significant at the 5 % level. In other words, the estimated values by these models are statistically consistent with the measured data. Overall, given the simplicity and performance, the Ångstrom model is the best choice for estimating solar radiation when sunshine duration measurements are available; otherwise, Bristow and Campbell can be used to estimate solar radiation using daily range of air temperature.